Jurassic, Golden Age - Tendaguru Formation

As the sun sets and its golden rays slowly disappear, life is still active in the Tendaguru Formation. Here, during the Late Jurassic where is now Tanzania, there was a tropical savannah in a coastal region marked by rainy seasons. In the scene, the clouds and lightning announce the arrival of another period of heavy rains.

The area close to the coast was poor in vegetation, but the uplands, like those illustrated, were home to a variety of conifers. There are records of Cupressaceae, Taxaceae, possibly shrubby Podocarpaceae, large and common Araucariaceae and, finally, what would be the most numerous trees in the environment, the Cheirolepidiaceae. Other known plants depicted here include ginkgophytes, cycads and, forming the lowest vegetation, rare ferns.

Such a variety of conifers allowed large sauropods to thrive, feeding on the tall vegetation. In the image we see, in the foreground, a Giraffatitan brancai feeding on a Cheirolepidiaceae. Without realizing it, the giant bothers a swarm of Mecoptera (whose living species are popularly known as "scorpionflies"), important gymnosperm pollinators during the Mesozoic. The agitation of the insects attracts the attention of a Brancatherulum tendagurense, a small mammal that is among the lowest branches of the tree, and will try to catch some of these invertebrates.

Giraffatitan was quite common in the region (in fact, it is the sauropod with the most abundant fossil record of the Formation), and more individuals are seen walking in the distance. Its undisputed height, approximately 13 m, allowed this Macronaria to reach trees without competing with other species. Other sauropods seen there are contrasting forms: Diplodocoids, shorter and longer (especially due to their long, whip-like tail). There is a group of Dicraeosaurus hansemanni, with its modest size among sauropods (~15 m), feeding on bushes and smaller trees; Further away we can see a trio of Tornieria africana, a species of large proportions (around 25 m in length).

It is worth noting that the sauropods are depicted with a cornified covering on their snouts, similar to a beak. The possibility has already been brought up a few times by different authors, the most recent example being Garderes et al. (2023) for Bajadasaurus.

Other herbivores also consume medium and low vegetation, seeking out conifer shrubs, cycads and ferns. At the margins of the lake, 2,5 m long ornithopods Dysalotosaurus lettowvorbecki forage among the ferns while closely following a Giraffatitan. The giant's "escort" not only provides protection, as it discourages the approach of predators, but also offers additional food through leaves it might drop from tall trees or even through its feces that may occasionally be of interest to the Dysalotosaurus when they search for extra nutrients.

On the other side of the scene, attentive to something in common, are some Kentrosaurus aethiopicus, 4.5 m stegosaurs with notable plates and spines along their back, and a 6 m long Elaphrosaurus bambergi, which walks alone. This was a theropod that, assuming it was like its close relative, Limusaurus, was a toothless herbivore/omnivore (losing its teeth as it grew, keeping only the beak in adult life). What keeps these dinosaurs on alert is a Veterupristisaurus milneri, a predator measuring at least 8 m, which rests under a tree not too far away.

The carcharodontosaurid isn't the only predatory theropod in sight. In the lake, an Ostafrikasaurus crassiserratus has just caught a fish. The real identity of this carnivore is mysterious, as it is a dinosaur described solely on teeth. The illustration uses the originally proposed classification, a basal spinosaurid, but an alternative origin for these teeth has since been proposed, the Ceratosauridae. The fish it catches is Lepidotes tendaguruensis, a small species (25 cm) within this widely distributed genus.

The presence of the spinosaur intimidates some pterosaurs (previously described as 'Rhamphorhynchus tendagurensis', today a dubious name) who also search for fish. They continue flying over the lake, but will wait for the dinosaur to leave before descending to the water nearby. Other smaller pterosaurs, Tendaguripterus recki with a wingspan estimated at ~1 m, fly in groups at a higher altitude - experiencing, together with the Giraffatitan, the last rays of the sun from that day.

New artwork for Tales from the Phanerozoic, a project by João Macêdo. Check out the Jurassic chapter here, with the backstory of the scene and detailed information about its environment and creatures:

https://sites.google.com/view/talesfromthephanerozoic/the-mesozoic/middle-of-a-golden-age